In a conventional prediction type electronic clinical thermometer, prediction operation starts at a time when the actual measurement value is equal to or more than a predetermined value and the rate of temperature rise is equal to or more than a predetermined value. A prediction settling point is given at a time when a variation in prediction value falls within a predetermined value. A prediction value Y is generally given by Y=T+U where T is the actual measurement value and U is the additional value.
A variety of calculation methods provide the additional amount U, and examples of the calculation methods are U=a1×dT/dt+b1 and U=(a2×t+b2)×dT+(c2×t+d2)
The parameters a1, b1, a2, b2, c2, and d2 are constants selected to keep the precision of the additional amount U constant regardless of patients and temperature detection elements.
Parameters used for prediction calculation equations are grouped depending on the features of patients and the characteristics of temperature detection elements. In particular, there is disclosed a technique for determining parameter groups based on actual measurement values of the temperature detection element to allow prediction with a higher precision. There is also disclosed a technique for changing corresponding parameter groups based on temporal changes in prediction values upon determining the parameter groups to allow prediction with a higher precision (patent reference 1).
Upon power-on of an electronic clinical thermometer, data necessary for temperature measurement such as temperature measurement parameters are read out from a nonvolatile memory such as an EEPROM. A conventional arrangement reads out these data immediately after power-on.
Upon power-on of the electronic clinical thermometer, when the thermometer is to be inserted into an underarm of a user and the metal cap at its distal end comes into contact with an electrostatically charged piece of clothing worn by the user, the thermometer may fail to read out the data necessary for temperature measurement due to an electrostatic influence. When the conventional clinical thermometer fails to read out data from the EEPROM, it informs the user of a temperature measurement error and prompts him to retry the temperature measurement (patent reference 2).    Patent Reference 1: Japanese Patent No. 3100741    Patent Reference 2: Japanese Patent Laid-Open No. 59-114424